Need advice for a modified case

[Bill Daniel]

For my Henry 45-70 to feed the Hornady Lever Revolution 325 grain I've had to trim the case 0.045". Can I simply recharge the cartridge with the same powder charge that came from the cartridge when I pulled the bullet or will that yield a dangerous pressure spike because I reduced the case volume?
Thanks,
Bill

[g.willikers]

Any changes like that can, and probably will, change lots of other things.
That's why the loading manuals and web sites warn against getting creative with load data.
Unless you have testing equipment like the manufacturers, it's best to stay with published data and tested components.
The amount that you are trimming is only 2% of the total case length, but,
You can make guesstimates and observe results, but there's really no way to know for sure.
It sounds like either a shorter bullet is needed, or less powder and the use of a chronograph, at the very least.
And, as with any load, always check for high pressure signs.

[F. Guffey]

For my Henry 45-70 to feed the Hornady Lever Revolution 325 grain I've had to trim the case 0.045".

I will assume you removed a 325 grain bullet then replaced it with another 325 grain bullet. Then I will assume the bullets in appearance are different but still weigh the same.

I make these assumptions because you shorten the case .045", if the powder charge stays the same and the bullet is heavier and the case gets shorter you could render your rifle scrap, something like the Old Deacons Master Piece, nothing before then suddenly and without warning in lay in a heap.

F. Guffey

[Snyper]

Need advice for a modified case

My advice would be if it doesn't fit the gun to begin with, try a different load

I'm not sure why you'd trim the brass to make it fit when it should already be within industry specs

[Nathan]

I woul like to hear the logic of how the case needs to be 0.045" shorter.

What is the source of the original loading?

Also, how are you doing this without contaminating the powder?

Are the before and after bullets the same?

Are the OAL's the same?

Probably not, but your proposal could be safe, if many things are accounted for.

[William T. Watts]

Hornady Lever Revolution 325 grain is why he shortened the case, I would think the length of the bullet is longer and in order to feed properly the case must be shortened and powder capacity reduced. The original poster didn't mention these points but Hornady did some creative engineering and came up with this result. I do not use this bullet and see no need to, these bullets were designed for lever action calibers and no amount of engineering is going to change they are what they are slow and heavy bullets with limited range. My advice would be if this is a round that Hornady is loading I would buy at least one box to disassemble and examine a couple of rounds for a better idea of what your dealing with.. William

[Bill Daniel]

Thanks to all. Just to clarify. The Hornady Lever Revolution is a Spire shaped bullet but with a flexable tip so that I will not set off the primer of the next bullet in a tubular magazine under recoil. The case for this bullet was reduced by Hornady from 2.105" to 2.040" as the spire shaped bullet changed the COAL from 2.55" to 2.70" and I would not feed from the tubular magazine of the Winchester or Marlin. The factory cartridge has a COAL of 2.60" and will not feed from my rifle magazine. By trimming the brass 0.045" I reduced the COAL to 2.555" with the crimp at the bullet cannelure. This allows it to feed from my magazine. As to why, it is because I other wise have a box of shells that is useless for hunting unless loaded one at a time. The bullets are pulled one at a time with an impact tool and the power is thus not mixed with any other. The same bullet I pulled is the one I replaced. I bought the box of Lever Revolution cartridges because the Hornady 325 grain flex tips would not feed on my reloads when I trimmed my brass from 2.105 to 2.040 as recommended by Hornady so I wanted to see if I was doing something wrong and the factory cartridge was different from my reload. When I measured and found them the same and could see that the bullet tips protruding kept it from feeding I decided to reduce the COAL to 45-70 Government specs. of about 2.55".
The goal was not to make the 45-70 into a long range hunting rifle but in search of a more accurate round. I also do not have a death wish and if my plan is dangerous I will find some one at my gun club with a Marlin or Winchester to see if the remaining 19 cartridges will function in their gun.
What say yea TFLers.
Thanks,
Bill

[William T. Watts]

I've considered this bullet and have decided I didn't want to play with it, whatever gain there was lies mostly in some Hornady engineers imagination. There's lots of bullets out there that have been around a lot of years that work well and are proven game bullets and less expensive. The rifle you have isn't a target rifle and for most applications if a rifle of this type will shoot 3' groups at 100yds it certainly is more than adequate for hunting white tails.. Besides the question of reducing the powder charge when the length of the case was reduced would have to be factored in also.. Non the less best wishes and good luck with the rifle. I am partial to the lever gun and the history of it, I have a 307 Winchester that I have a fondness for, I intend to use it for this years deer hunt!! William

[hartcreek]

I would use these up for hunting, I do something similar with 25-35 and .32 Winchester. I load spire points of the same weight for my first shot for single round placement right in the chamber.

20 rounds would barely be enough to test to see if it actually shot better.

[Unclenick]

Bill,

You want to calculate how much case water capacity in grains of water weight is lost by seating the bullet deeper, then reduce the powder charge by about 0.6 times that weight. It's a very rough approximation, but tends to keep peak pressure about the same in most modern rifle cartridges. It comes from ratios published by Wm. C. Davis in the American Rifleman long ago. QuickLOAD agrees that it works out to be close to true most of the time.

((0.5 × 0.0458 in)² × π) × 0.045 in = reduced volume in in³ = .007414 in³

4°C Water density is 252.9 grs/in³

So 0.007414 in³ × 252.9 grs/in³ = 1.875 grs water capacity reduction

1.875 grs × 0.6 = 1.125 grs reduction in powder charge.

[Snyper]

The explanation makes sense, but after all that work I'd expect one hole groups or I'd never do it again

[Bill Daniel]

Thanks Unclenick!! As the brass is 0.15" shorter than standard and all reloading formulas use standard length brass can I use the same method to calculate a starting load for my powders?
Though as Snyper noted the improvement will need to justify the effort
Thanks again,
Bill

[William T. Watts]

Keep it simply, measure the case expansion of fired factory ammunition at the expansion ring with a good quality mic with a ten thousand graduation scale "if" the handloaded ammunition expansion ring is equal to or less than factory ammunition they will be safe to shoot. Remembering even one ten thousand of an inch of expansion over the factory ammunition expansion ring is evidence of higher than desired pressure. This concept is a heck of a lot easier to digest than Unclenicks explanation and much easier to understand.. I've never had a primer to leak nor pierced one in 45 years of loading ammunition. It would help if people would be more willing to read at least a couple of reloading manuals to acquire a bit better understanding of what they are doing.. William

[Bill Daniel]

Good thought William. But Unclenick's plan will keep that first bullet from blowing my rifle to pieces After that I can check for case head expansion.
Over and out.
Bill

[William T. Watts]

Good luck Bill!! William